This invention generally relates to the art of electrical connectors and, particularly, to connectors for electrically interconnecting a plurality of discrete terminal pins to the conductors of a flat flexible circuit.
A flat flexible circuit conventionally includes an elongated flat flexible dielectric substrate having laterally spaced strips of conductors on one or both sides thereof. The conductors may be covered with a thin, flexible protective layer on one or both sides of the circuit. If protective layers are used, cutouts are formed therein to expose the underlying conductors at desired contact locations where the conductors are to engage the conductors of a complementary mating connecting device which may be a second flat flexible circuit, a printed circuit board or the terminals of a mating connector.
A wide variety of connectors have been designed over the years for terminating or interconnecting flat flexible circuits with complementary mating connecting devices. However, there has not been a reliable and cost effective system for electrically connecting a plurality of discrete terminal pins to flat flexible circuitry. The present invention is directed to satisfying that need and solving the problems associated therewith. The present invention is extremely simple, inexpensive and reliable.
An object, therefore, of the invention is to provide a new and improved electrical connector for interconnecting the conductors of a flat flexible circuit to a plurality of discrete terminal pins.
In the exemplary embodiment of the invention, the connector includes a dielectric housing having a front mating face and a rear terminating face. The front mating face has a plurality of terminal pin-receiving passages. The terminating face has a flat circuit-receiving receptacle which is in communication with the passages. A circuit carrier or spring member is insertable into the receptacle and includes an attachment portion for attaching the flat flexible circuit to the carrier, with the conductors of the circuit facing away from the carrier toward the terminal pin-receiving passages. Insertion of the pins into the passages causes the pins to engage the conductors of the circuit.
The circuit carrier preferably is fabricated of metal material and includes a spring loaded mouth into which the terminal pins are inserted into engagement with the conductors of the circuit. The housing includes cam means engageable with the circuit carrier to open the spring loaded mouth a given amount to apply a given contact force between the terminal pins and the conductors of the circuit. Complementary interengaging latch means are provided between the circuit carrier and the housing to hold the carrier in the receptacle of the housing. The leading edge about which the flat flexible circuit is wrapped is a thin or abrupt edge which provides an interference engagement with the flat flexible circuit to retain the circuit supported by the circuit carrier or spring member.
As disclosed herein, at least a portion of the circuit carrier is generally U-shaped to define a pair of legs. A first of the legs forms the attachment portion of the carrier. A second of the legs forms a mounting portion for mounting the circuit carrier in the housing. The first leg has a leading edge about which the flat flexible circuit is wrapped, with the conductors of the circuit facing away therefrom. A raised area is provided immediately inside the leading edge of the first leg and over which the flat flexible circuit is wrapped. The raised area forms contact portions of the terminals for engaging the terminal pins. The raised area may be provided by a yieldable backing strip adhered to the first leg. The distal ends of the legs define the mouth into which the terminal pins are inserted. The cam means for opening the mouth comprises at least one cam ramp on the housing for engaging the first leg of the circuit carrier to open the mouth automatically in response to inserting the circuit carrier into the receptacle in the housing.
In one embodiment of the invention, the cam means which is engageable with the circuit carrier or spring member to open the spring loaded mouth thereof is integral with the housing. In a second embodiment, the cam means is integral with a preload member which is separate from the dielectric housing. The preload member is mounted on the housing for movement between a preassembly position wherein the cam means is out of engagement with the spring member and a preload position wherein the cam means is in engagement with the spring member opening the spring loaded mouth thereof.
As disclosed herein, the separate preload member is slidably mounted in an opening at the front mating end of the housing for movement between the preassembly and preload positions. The preload member includes a plurality of terminal pin receiving passages. The conductors of the flat flexible circuit are spaced laterally thereof, and the terminal pin receiving passages are aligned with the conductors. The cam means is provided by a plurality of individual cams located between the terminal pin receiving passages. Finally, detent means are provided between the preload member and the housing to hold the preload member in either of the preassembly or preload positions.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.